This invention relates to game balls, and, more particularly, to an inflatable game ball with a carcass and a cover.
Game balls such as basketballs, soccer balls, and footballs conventionally include an inflatable bladder and a cover. The bladder may be reinforced with windings of nylon thread, polyester thread, etc. The cover is conventionally formed from panels of cover material, for example, leather, synthetic leather, or rubber. Adjacent panels are separated by rubber channels.
The portion of the ball excluding the cover is conventionally referred to as the carcass. Historically, basketballs have been made by first forming an inflatable rubber bladder, inflating the bladder, and molding the bladder under heat and pressure to vulcanize the rubber. After the bladder is removed from the mold, the bladder is wound with reinforcing thread which forms a layer of windings. The thread may be dipped in latex or adhesive. Pieces of rubber are then laid over the wound bladder, and the rubber-covered wound bladder is molded under heat and pressure to vulcanize or cure the pieces of rubber and to fuse the pieces of rubber to each other and to the layer of windings. The molded product is the carcass.
The surface of the carcass mold is provided with grooves which form upwardly extending projections on the surface of the carcass. The projections will form the seams or channels of the completed ball. The portions of the carcass between the channels are spherical. Panels of cover material are laid into the areas of the carcass between the channels, and adhesive may be applied to the cover panels and/or the carcass. The covered carcass is placed in a mold having the shape of the completed ball to form the ball under heat and pressure.
Leather covered basketballs have conventionally used relatively thick leather panels, for example, having a thickness of about 1.6 mm. The leather material was often originally designed for use in shoes and was therefore thicker than may have been necessary for a basketball cover.
Skilled workers who apply cover panels to basketballs have traditionally tapered or skived the edge portions of the cover panels which are adjacent the channels. The cover panels are therefore relatively thick over the portions of the ball between the channels and relatively thin and tapered adjacent the channels.
The varying thickness of each cover panel provides the basketball with a lobular outer surface which includes lobes between the channels. The portion of most of the outer surface between adjacent channels is generally spherical, but the portions of the outer surface adjacent the channels are depressed or recessed.
A lobular surface on a basketball is preferred by many players because it is easier to grip. As a result, many basketballs are made with a lobular surface even if the cover panels are not genuine leather. The lobular surface may be provided in the conventional manner by using relatively thick cover panels which are tapered or skived in the edge portions which are adjacent the channels.
The cost of the cover is a major factor of the cost of a basketball. That is particularly true for leather covers, but is also true for synthetic leather and other cover materials such as polyurethane and PVC. Decreasing the thickness of the cover would decrease the cost of the ball. However, a thinner cover could not be skived to provide the desired lobular surface.